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@@ -5,44 +5,43 @@ in your supervision tree. This allows for greater fault tolerance
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control by permitting the shutdown of a listener due to the
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failure of another part of the application and vice versa.
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+However, just as for non-embedded listeners that were started via
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+`ranch:start_listener/5`, it is required that the `ranch` application
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+is running before you can start embedded listeners. Furthermore,
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+this also means that embedded listeners will restart when `ranch_sup` fails.
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+
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+WARNING: By using embedded mode, it is possible to start a listener with the same name
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+as an already existing listener. This will corrupt the information Ranch
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+keeps for that listener, so you should take care to ensure unique listener
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+names yourself. A good way to achieve this is by combining the embedded
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+listener's name with `?MODULE`, or the name of the application it is used
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+in.
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+
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=== Embedding
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To embed Ranch in your application you can simply add the child specs
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to your supervision tree. This can all be done in the `init/1` function
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of one of your application supervisors.
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-Ranch requires at the minimum two kinds of child specs for embedding.
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-First, you need to add `ranch_sup` to your supervision tree, only once,
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-regardless of the number of listeners you will use. Then you need to
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-add the child specs for each listener.
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-
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Ranch has a convenience function for getting the listeners child specs
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called `ranch:child_spec/5`, that works like `ranch:start_listener/5`,
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except that it doesn't start anything, it only returns child specs.
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-As for `ranch_sup`, the child spec is simple enough to not require a
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-convenience function.
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-
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-The following example adds both `ranch_sup` and one listener to another
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-application's supervision tree.
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+The following example adds one listener to another application's
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+supervision tree.
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.Embed Ranch directly in your supervision tree
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[source,erlang]
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----
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init([]) ->
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- RanchSupSpec = {ranch_sup, {ranch_sup, start_link, []},
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- permanent, 5000, supervisor, [ranch_sup]},
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- ListenerSpec = ranch:child_spec(echo, 100,
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- ranch_tcp, [{port, 5555}],
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+ ListenerSpec = ranch:child_spec({?MODULE, echo},
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+ ranch_tcp, #{socket_opts => [{port, 5555}]},
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echo_protocol, []
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),
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- {ok, {{one_for_one, 10, 10}, [RanchSupSpec, ListenerSpec]}}.
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+ {ok, {#{}, [ListenerSpec]}}.
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----
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-Remember, you can add as many listener child specs as needed, but only
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-one `ranch_sup` spec!
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-
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-It is recommended that your architecture makes sure that all listeners
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-are restarted if `ranch_sup` fails. See the Ranch internals chapter for
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-more details on how Ranch does it.
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+Embedded listeners cannot be stopped via `ranch:stop_listener/1`. Instead,
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+are to be stopped as part of the shutdown of your application's supervison
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+tree.
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